连续梁桥上CRTS双块式无砟轨道疲劳特性

为探讨梁轨非线性互制作用下连续梁桥上双块式无砟轨道系统静动力荷载下结构响应，预测桥上无砟轨道结构的疲劳寿命，基于梁轨相互作用原理与车辆-轨道-桥梁耦合动力学原理，以昌景黄铁路某(40+64+40)m连续梁为研究对象，采用有限元方法建立了考虑桥梁、支座、底座板、道床板、扣件和钢轨等构件及结构层间非线性约束的连续梁-CRTS双块式无砟轨道的一体化空间分析模型，研究列车静活载作用下桥梁、道床板、底座板及钢轨的动力响应特性与无缝线路纵向力分布规律，分析连续梁桥上无砟轨道结构疲劳特性。结果表明：温度荷载作用下钢轨最大压应力位于连续梁两端，最大拉应力位于桥梁跨中；竖向荷载作用下钢轨最大拉应力位于连续梁桥墩，最大压应力位于桥梁跨中；制动荷载作用下钢轨拉、压应力极值均位于桥梁桥墩；钢轨纵向力由温度荷载控制，最大应力为143.1 MPa,满足规范要求；列车动载作用下，简支梁和连续梁上钢轨最大拉、压应力相当，道床板最大拉应力出现在连续梁跨中限位凹槽附近，其板底拉应力大于板顶，底座板最大拉应力出现在连续梁主墩附近，且板顶和板底的拉、压应力基本相同；列车动载作用下，钢轨最易破坏处寿命约27.1 a,道床板和底...

Fatigue characteristics of CRTS bi-block ballastless track on continuous bridge of high-speed railway

In order to investigate the structural response of CRTS Bi-block ballastless track system on continuous bridge under dynamic train load, and predict the fatigue life of the ballastless track structure on the bridge, based on the principle of bridge-rail interaction and train-track-bridge coupling dynamics, a (40+64+40)m continuous bridge of Nanchang-Jingdezhen-Huangshan high speed railway is taken as the research object, the refined simulation model of continuous beam bridge-ballastless track system considering the nonlinear constraints between bridge, bearing and abutment, shear nail, baseplate, elastic cushion, track plate, fastener and rail is established by using the finite element method. The dynamic response characteristics of coupling system and the longitudinal force distribution law of CWR are studied, and the structural fatigue characteristics of ballastless track laid on continuous beam bridge are analyzed. The results show that: the maximum compressive stress of rail under temperature load appears at both ends of continuous beam, and the maximum tensile stress appears in the middle of bridge span. The maximum tensile stress of rail under vertical load appears near the pier of continuous beam bridge, and the maximum compressive stress appears in the middle of bridge span. Under the action of braking load, the maximum tensile and compressive stress of rail appear near the bridge pier. The longitudinal force of the rail is controlled by the temperature load, and the maximum stress is 143.1 MPa, meeting the specification requirements; Under the action of dynamic train load, the maximum tensile and compressive stress of rail on simply-supported bridge and continuous bridge are equivalent. The maximum tensile stress of track plate appears near the limit groove in the middle span of continuous beam bridge, the tensile stress at the bottom surface of track plate is greater than that at the top surface. The maximum tensile stress of the baseplate occurs near the main pier of the continuous beam bridge, the tensile and compressive stress at the top and bottom surface of the baseplate are basically the same. Under the action of dynamic train load, the service life of the most vulnerable part of the rail is about 27.1 years, and there will be no fatigue failure to track plate and baseplate during service.